Empfingen, Germany – The German Aerospace Center (DLR) has announced a significant breakthrough in hydrogen fuel cell technology, successfully operating a fuel cell system and associated electric motor components at more than one megawatt of power. This milestone, achieved at DLR’s BALIS test infrastructure, marks a critical step towards realizing carbon dioxide-free propulsion for heavy-duty road vehicles, ships, and aviation.
The propulsion systems under development by DLR are designed to output up to 1.5 megawatts (2,011 hp) and could revolutionize various sectors requiring substantial power outputs.
DLR’s BALIS Project: Scaling Fuel Cell Power
The BALIS (Bavarian Advanced Light-weight Integrated System) project aims to develop and test fuel cell electric propulsion systems in the megawatt range. Researchers at the E2U Empfingen Development Centre for Environmental Technology innovation campus have successfully operated two core components—the fuel cell system and the electric motor—each exceeding one megawatt.
“This is an important milestone in the set-up and commissioning of the test facility and the first generation of the fuel cell test system,” stated Cornelie Bänsch, project leader from the DLR Institute of Engineering Thermodynamics. “Systems of this power class are not yet available on the market. The technical challenge lies in developing and integrating all the components so that they operate stably at high outputs of one megawatt or more.”
The system currently comprises 12 electrically coupled fuel cell modules, each containing over 400 individual fuel cells that exchange information and interact to power the propulsion system. DLR researchers are focused on developing sophisticated operating strategies to control this complex setup and aim to operate the test system stably for extended periods while increasing output above one megawatt. Future plans include running dynamic profiles with varying high power outputs to simulate real-world operating conditions for different durations.
Implications for Sustainable Transportation
The successful operation of a megawatt-class hydrogen fuel cell system by DLR holds immense promise for decarbonizing hard-to-electrify transport sectors. Hydrogen fuel cells, powered by green hydrogen, offer a pathway to carbon dioxide-free mobility and can significantly reduce dependence on fossil fuels.
Electric Aviation Potential
For aviation, where weight and power requirements are stringent, the development of megawatt-scale fuel cells is transformative. This technology could enable larger, longer-range electric aircraft, moving beyond the limitations of current battery technologies which struggle with the energy density needed for sustained flight. Distributed electric propulsion architectures, where multiple electric motors power an aircraft, could benefit significantly from such powerful and efficient fuel cell systems.
Heavy-Duty Road Vehicles and Maritime Shipping
Beyond aviation, the DLR’s breakthrough also has direct applications for heavy-duty road vehicles and maritime shipping. These sectors require continuous high power and rapid refueling, attributes that hydrogen fuel cells inherently provide. Companies like Plug Power, Ballard Power Systems, and Nikola Corporation are already advancing hydrogen fuel cell solutions for commercial vehicles, trucks, buses, and marine vessels, with projects demonstrating viability and environmental benefits.
MIT’s Sodium-Air Fuel Cell: A Parallel Energy Density Leap
In a separate, but equally impactful development, researchers at the Massachusetts Institute of Technology (MIT) have unveiled a novel sodium-air fuel cell technology that offers unprecedented improvements in energy density, cost-effectiveness, and environmental sustainability. This breakthrough, published in the journal Joule, directly addresses the energy density bottleneck faced by conventional lithium-ion batteries, particularly for aviation.
Redefining Energy Storage for Electric Transport
Unlike traditional batteries, which store energy in a fixed chemical form, MIT’s innovative fuel cell leverages liquid sodium metal as a fuel source and ambient air as its oxidizer. This “true” fuel cell design allows for rapid refueling, akin to pumping gas, rather than lengthy recharging.
The prototype device has demonstrated an energy density exceeding 1,500 watt-hours per kilogram at the cell stack level, projecting to over 1,000 watt-hours per kilogram at the full system level. This is more than three times the energy per unit of weight compared to today’s best EV lithium-ion batteries, which typically top out around 300 watt-hours per kilogram.
Impact on Aviation and Other Sectors
Professor Yet-Ming Chiang, from MIT’s Department of Materials Science and Engineering, highlights that reaching 1,000 watt-hours per kilogram is a critical threshold for practical regional electric aviation. Regional flights constitute about 80 percent of domestic flights and account for approximately 30 percent of aviation emissions.
The core of the system is a high-temperature ceramic electrolyte that enables sodium ions to move between a reservoir of liquid sodium metal and a porous air cathode. Crucially, sodium is an abundant and inexpensive material, often derived from common rock salt, making the technology potentially cost-effective and environmentally friendly. This sodium-air fuel cell could also catalyze the electrification of marine vessels and trains, which also require high energy density and low operational costs.
The Future of Fuel Cell Technology
These concurrent breakthroughs by DLR and MIT underscore a pivotal moment in the advancement of fuel cell technology. While DLR’s achievement demonstrates the successful scaling of hydrogen fuel cell power to megawatt levels for heavy transport, MIT’s sodium-air fuel cell offers a distinct pathway to high energy density for applications like aviation, bypassing the limitations of existing battery chemistries.
Continued research and development are essential to overcome challenges such as cost, infrastructure development, and long-term durability. However, with these latest advancements, fuel cells are increasingly positioned to play a crucial role in the global transition towards sustainable, zero-emission transportation across all sectors.
